Support fast case for-in in Crankshaft.

src/ast.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 768 matching lines @@
 
   void Initialize(Expression* each, Expression* enumerable, Statement* body) {
     IterationStatement::Initialize(body);
     each_ = each;
     enumerable_ = enumerable;
   }
 
   Expression* each() const { return each_; }
   Expression* enumerable() const { return enumerable_; }
 
-  // Bailout support.
-  int AssignmentId() const { return assignment_id_; }
   virtual int ContinueId() const { return EntryId(); }
-  virtual int StackCheckId() const { return EntryId(); }
+  virtual int StackCheckId() const { return body_id_; }
+  int BodyId() const { return body_id_; }
+  int PrepareId() const { return prepare_id_; }
 
  protected:
   template<class> friend class AstNodeFactory;
 
   ForInStatement(Isolate* isolate, ZoneStringList* labels)
       : IterationStatement(isolate, labels),
         each_(NULL),
         enumerable_(NULL),
-        assignment_id_(GetNextId(isolate)) {
+        body_id_(GetNextId(isolate)),
+        prepare_id_(GetNextId(isolate)) {
   }
 
  private:
   Expression* each_;
   Expression* enumerable_;
-  int assignment_id_;
+  int body_id_;
+  int prepare_id_;
 };
 
 
 class ExpressionStatement: public Statement {
  public:
   DECLARE_NODE_TYPE(ExpressionStatement)
 
   void set_expression(Expression* e) { expression_ = e; }
   Expression* expression() const { return expression_; }
 
@@ skipping 2006 matching lines @@
  private:
   Isolate* isolate_;
   Zone* zone_;
   Visitor visitor_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_